As a method for suppressing blur (image blur) in a photographed image due to a camera shake or the like in an image pickup apparatus, there is known an optical-type blur suppressing process which drives a vibration reduction optical system in accordance with blur that occurred, the vibration reduction optical system being provided to constitute a part of an image pickup optical system. In addition, a photographed image, which is obtained via the image pickup optical system, distorts due to an influence of distortion or the like of the image pickup optical system. Such distortion or the like is, in usual cases, corrected by a geometrical conversion process. In an image pickup apparatus which is proposed in Jpn. Pat. Appln. KOKAI Publication No. 2015-015587 (patent document 1), a component (dynamic component), which varies due to decentering of the image pickup optical system by the driving of the vibration reduction optical system, and a component (static component), which does not vary, are divided, and the distortions of the respective components are individually corrected, thereby to improve the precision of distortion correction.
However, in the method of patent document 1, since two distortion corrections are executed, the processing load increases. In addition, since parameters for correction, which are used in the respective distortion corrections, are needed, a necessary memory resource increases.